Elmer e



E. E. WICKERSHAM.

POSITIVE REDUCTION CLUTCH.

APPLICATION man MAY5. 1919.

6 SHEETS-SHEET I.

Fig].

INVENTOR ZZmerZ/Wciera/Emfl ATTORNEY- E. E. WICKERSHAM.

POSITIVE REDUCTION CLUTCH.

' APPLICATION FILED mm. 1919.

E E. WICKERSHAM.

POSITIVE REDUCTION CLUTCH.

APPLICATION FILED MAY 51 1919.

1 ,407,97 1 Pafi ntati Feb. 28, 1922.

6 SHEETS-SHEET 3- E. E. WICKERSHAM.

POSITIVE REDUCTION CLUTCH.

APPLICATION FILED MAY 5, 19H).

Patented Feb. 28, 1922.

6 SHEETSS?'IEET 4.

INVENTOR ATTORNEYS E. E. WICKERSHAM.

POSITIVE REDUCTION CLUTCH.

APPLICATION FILED MAY5|1919.

Patented Feb.28,1922. I

6 SHEETSSHEET 5- Z? 7? Fig INVENTOR I illrzarlflfdfi's/am I ATTORNEY5 E.E. WICKERSHAM.

POSITIVE REDUCTION CLUTCH.

APPLICATION FILED MAY 5, 1919.

1,407,97 1. Patented Feb. 28, 1922.

6 SHEETS-SHEET 6.

INVENTOR [[272 @2 27 fi ia?ens%wz WWW ATTORN EYS UNITED STATES PATENTOFFICE.

ELMER E. WICKERSHAM, OF STOCKTON, CALIFORNIA, ASSIGNOR TO THE HOLT MANU-FACTURING COMPANY, OF STOCKTON, CALIFORNIA, A CORFORATION OF CALI.

FORNIA.

POSITIVE-REDUCTION CLUTCH.

Specification of Letters Patent.

Patented Feb. 28, 1922.

To all whom it may concern:

Be it known that I, ELMER E. l/Vroxna SHAM, a citizen of the UnitedStates, residing at Stockton, in the county of San Joaquin and State ofCalifornia, have invented new and useful Improvements inPositivaReduction Clutches, of which the following is a specification.

This invention relates to a vehicle transmission and particularlypertains to a positive reduction clutch therefor. In vehicles used forheavy hauling and for drawing heavy loads such as tractors, it is commonto steer the vehicle by changing the relative driving speeds of therunning gear upon opposite sides of the vehicle main frame.

' It is the principal object of the present invention to provide atractor transmission embodying positive reduction clutches which may jbe controlled to make any desired change in the driving speeds of thetruck mechanisms by a simple means which will not dissipate the drivingforce and which will act in itself, to positively make the re ductiondesired.

The present invention contemplates the use of a two-piece driving axle,the separate units of which may be simultaneously driven by a speedchanging transmission and which units may be individually controlled torotate at the same or different rates of speed.

The invention is illustrated by way of example in the accompanyingdrawings, in which c Fig. 1 is a view in side elevation, illustrating acomplete tractor fitted with the present invention.

Fig. 2 is a view in verticalse'ction taken longitudinally of the tractortransmission, along the line 2-2 of Fig. 5.

Fig. is a view in vertical section on the line 33 of Fig. 2, showing thereversing gear arrangement.

Fig. 1 is a view in horizontal section, as seen on the line 4 1 of Fig.2, showing the gear pump.

Fig. 5 is a view in plan, illustrating the driving gears of the rearaxles and their connection with thetransmission gears.

Fig. 6 is anenlarged fragmentary view through the transmission on theline 6-6 of Fig. 5.

Fig. 7 is a. view in vertical section through the rear axle and thespeed controlling units, as seen on the line 77 of Fig. 5.

Fig. 8 is a fragmentary view in section and elevation, illustrating thegear mounted upon the end of the driving axle.

Figs. 9 and 10 are fragmentary views, disclosing the operation of theclutch brakes.

Fig. 11 is a view through one of the positive driven clutches, as seenon the line 11-11 of Fig. 13.

Fig. 12 is a view through one of the positive driven clutches, as seenon the line 1212 of Fig. 13.

Fig. 13 is a view in longitudinal central section through one of theclutches.

Fig. 14; is a View in vertical section through one of the clutches, asseen on the line 1 1l 1 of Fig. 11.

Fig. 15 is a view showing the planetary reduction gears of the clutch.

Fig. 16 indicates a gear train incorporated within the clutchconstruction. 1

Fig. 17 is a View in section and elevation, showing a modified form ofclutch structure, as seen on the line 1"Z-17 of Fig. 19.

Fig. 18 is a view in section and elevation through the modified form ofclutch as seen on the line 1818 of Fig. 19.

Fig. 19 is a vertical section through the modified form of clutch.

Fig. 20 is a view in vertical section, showing the modified form of theclutch as taken on the line 20-20 of Fig. 18.

Referring more particularly to the drawings, 10 indicates a tractor mainframe here shown as supported. upon self-laying track units 11, whichare disposed upon the opposite sides of the main frame and in parallelrelation thereto. Generally considered, these units consist of truckframes 12 carrying load supporting rollers 13, which rollers rest uponthe lower run of a chain track 14. The forward ends of the truck frames12 are fitted with idler wheels 15, around which the chain track is led.At the opposite end of the truck frames are disposed driving sprockets16, over which the tracks pass and by which they are driven. Thesedriving sprockets are simultaneously or independently driven by thetransmission mechanism which forms the subject matter of the presentapplication.

Carried upon the forward end of the main frame is. a power plant 17,consisting in the present instance, of an internal combustion engine.connected by a shaft 18 to the drive shaft 19 of a speed changingtransmission mechanism 20. As shown in Fig. 2, the drive shaft 19 issuitably journaled in opposite end bearings 21 and 22 and anintermediate bearing 23. These bearings are all formed as part of thetransmission housing and hold the shaft in a rotatable condition anddisposed horizontally.

Mounted upon the shaft 19 between the bearings 21 and 23, are a largedriving gear 24, a small driving gear 25 and an intermediate drivinggear 26. These gears are all three keyed in permanent position upon theshaft and are intended to cooperate with sliding gears 27 and 28 splinedupon a sec ondary drive shaft 29. A shown in Fig. 3, the primary driveshaft 19 and the secondary drive shaft 29 are disposed with theirtransverse axes in vertical alignment. The gear 27 is intended to meshwith the gear 24 for high speed driving or with a reversing gear 30 fordriving in a reverse direction this gear 30 being in constant mesh withthe gear 26. The gear 28 is in tended to be brought to mesh with thegear 25 for low speed driving of the vehicle.

The shaft 19 extends through the end bearing 22 and is there fitted witha bevel gear .31 This gear is: in constant mesh with a bevel gear 32carried upon a pulley shaft 33. The pulley shaft extends at rightanglesto the shaft 19 and in the same plane therewith. This shaft is supported'within a separate housing 34, which may be removed from the endof themain transmission housing 21. The pulley shaft 33 is supportedwithin the housing 34 by means of'a fixed bearing 35 at one end of thehousing and a. sliding bearing 36 at the opposite end. The slidingbearing is carried with a cup 37 which fits snugly within the bore ofthe housing and which can be moved longitudinally. The cup 37 alsocarries a.

thrust bearing 38, taking up the end thrust produced by moving the gear32 into mesh with. thegear 31. The cup 37 and the bearings 36 and 38 arenot directly mounted upon the end of the shaft 33 but are mounted upon asleeve 39 formed as an extension of the hub of the gear 32,. the sleevebeing splined to the end of. the shaft 33 and driven thereby. Due tothis means. the gear will be supported and the end of. the shaftafforded a suitably bearing, which will perv init thegears 31 and 32 tobe readily moved into or out of engagement with each other.

main transmission and is supported by radial bearings 46 and thrustbearings 46.

.The gear 44 is adapted to drive the shaft 45 and this shaft in turn isprovided to simultaneously drive the. opposite ends of axle sections 47and 48. These sections are in longitudinal alignment with each. otherand are disposed beneath the transverse driving shaft 45. Each of theaxle members 47 and 48 are fitted with large driving gears 49, which arein mesh with driving pinions 50. Both of these pinions are mounted tocircumscribe the shaft 45 and are carried upon sleeves 51. The sleeves51 extend over the opposite ends of the shaft 45 and are fitted with.bushings 52, by which the shaft is directly supported.

Mounted upon the outer ends of the shaft 45 are gear frames 53 which areclearly shown in Fig. 11 and are provided for the support of worm gears54 and 55. The worm gears stand parallel to each other upon oppositesides of the axis of the shaft 45 and their shafts 56 are carried inbearings formed as a part of the gear frames 53. As clearly shown inFig, 12. the worm gears 54 and are fitted with driving pinions at theiropposite ends. These pinions are indicated at 58 and 59 and are in meshwith spur gears 60 and 6].. The spur gears 60 and 61 are fixed uponoppositely extending spindles 62 and 63. These spindles are free torotate Within bearings formed as a part of'the frame 53 and so designedas to dispose the spindles in longitudinal alignment with each other andwith the transverse xis of the shaft 45. The outer ends of the spindles62 and 63 are provided with bevel pinions 64 and 65. These pinions arein constant mesh with a bevel ring gear 66, here shown as formed aroundthe outer face of a gear drum 67. One of these drums is mounted for freerotation.

upon. each of the sleeves 51 and is further supplemented by a brake drum68, which provides a suitable brake circumference and will cause adriving action to be exerted upon the spur gears 50. This action willrotate the large spur driving gears 49 and will in turn drive the axlemembers t7 and 1S. The axles 4:7 and 18 extend oppositely from thecentral body portion of the gear casing and are enclosed within tubularsleeves 71. The sleeves 71 are fitted with inner and outer bearings 72and 73 for the support of the axles. The outer ends of these sleeves areclosed by caps 7%, as shown in Fig. 8. The outer ends of the axles aretapered and receive final drive pinions 75. These pinions are inseparate mesh with final drive gears 76, one of which is disposed ateach side of the transmission and is held in fixed relation to one ofthe/driving sprockets 16. As shown in Fig. 1, .it will be noted that thedriving sprockets 16 are mounted upon a dead axle 77. r

The brake drums 68 are each fitted with brake bands 78. Theends of thesebands are shown in Figs. 9 and 10 as being pivotally connected to abell-crank 7 9. Two bellcranks are provided and are fixed upon theopposite ends of a brake shaft 81. The brakeshaft 81 may be rotated inopposite directions by a Worm gear 82 secured to it at a point midwayits length and whichis in meshwith a complementary worm gear 83. Thislast named gear is fixed upon a steering shaft 84, rotatably supportedwithin a bearing 85 upon the transmission case. The shaft 84, whenoperated, will alternately rock the brake shaft 81 and set or releasethe brakes 68, as desired. By this operation, a variable amount offriction may be established between the brake bands and the drums toproduce a variation in the driving speed of the axles 47 and 418 in amanner hereinafter to be described.

As previously noted, the gear 27 and 28 are splined upon the secondarydrive shaft 29. Movement of these gears is effected by a shifting yoke80 carried by a shifting rod 87. This rod extends through slidingbearings in the case of the transmission and is formed with a hand-hold88 by which it may be shifted. Access to'these gears may be had throughan opening 89 in the top of the transmission .case, thisopening beingnormally closed by a cover 91. A cover is formed with a recess groove 92adapted to rest upon the edge of the opening and form ing sealtherewith. One edge of the cover is hinged to the transmissioncase by apin while the opposite edge isprovided with flanges 94 engageable by alock bolt 95. A breather opening 96 is formed in the top of the cover 91and is adapted to be partially closed by a cup member 97 secured inplace by a cap screw 98. a i

In order that the transmission may have positive and continuouslubrication, pipes 99 and 100 are mounted within the transmission case.The pipe 99 extends horizontally above the gear set and is perforatedthroughout its length. A suitable regulating valve is interposed at somepoint along the length of the pipe to regulate the lubrication. The pipe99 leads into a pump casing 102 detachably secured to the side of thetransmission and within which are positioned pump gears 103 and 1041.These gears are in constant mesh with each other and operate accordingto the well-known principle of pump construetion to deliver a liquidfrom the intalrc pipe 100 to the out-take pipe 99. The gears are drivenby means of a vertical shaft 105 extending upwardly through the casingand fitted with a driving gear 106 at its upper end, Thisgear is inconstant mesh with the bevel gear 31 carried by the end of the primarydrive shaft 19.

Referring to Figs. 17 to 20 of the drawings, it will be seen that amodified form of a positive reduction clutch is disclosed. In the formpreviously described, a reduction can be had to the point where thegears will stand idle and in this form there is never a reduction whichwill cause the gears to remain perfectly idle. This difference is, ofcourse, due to the variation in gear ratios existing between the variousgears of the train and also in the manner in which they are operated. Inthis modified form of the invention, the sleeve 51 is fitted with a wormgear 69. Upon the opposite ends of the frame 53, worm gears 51 and arerotatably supported. These gears are in driving re lation to other wormgears 110 and 111, sacured to the ends of their shafts and in constantmesh with complementary worm gears 112 and 113 respectively. The gears113 are fixed upon shafts 114i. and 115 which stand parallel to therotating axis of the sleeve and. the outer ends of each shaft are fittedin the gear frame Pinions 116 are in. mesh with ring gears 117 formed asa part of the brake drum structures 118. thus be evident that theoperation of the two devices is identical but that due to the differenceand arrangementof the gears and their ratios, a different reduction willtake place between thedriving shaft 415 and the sleeve 51.

In. operation. it will beassumed that the tractor is driving at lowspeed. Under these conditions, the gear 25 upon the primary drive shaft19 and the gear 28 upon the secondary drive shaft 29 will he in mesh. Ifit is desired to drive the vehicle at higher speed, the gears 24. andv27 are brought to mesh, as indicated in Fig. 2. Power will then betransmitted from the power plant through the shaft 19 to the gear 241and from thence to the gear 27 to drive the secondary shaft 29. As thisrotates, the bevel gear 13 will be driven and the large bevel gear 44.in mesh therewith. This rotation will drive It will the transverse shafta5 and will simultaneously rotate the gear frames 53 which are securedto the opposite ends of this shaft. Under normal conditions, it will beassumed that both of the brake drums 68 are free to rotate withoutrestriction from I the brake bands 78 and in this case the gear frames53, the worm gears 54, the small spur gears 58 and 59, the large spurgears 61 and 62, and the small bevel gears 6a and '75 will rotate inunison while rotating the gear drums 68. At this time the worm gears 5 fand 55 will lock upon the opposite sides of the driving worm gears 69and will thus cause both of the sleeves 51 to rotate in unison. Thesesleeves will rotate the spur pinions 50 and they in turn will drive thelarge driving gears 49. The axle sections 47 and 48 are fixed to thelarge gears 41-9 and will be thus driven thereby. The shafts 47 and willrotate the pinions 75 and driving motion will then be imparted to thedriving sprockets 16, through the final drive gears 7 6. In the eventthat a turn is to be made, the shaft 81 is rotated, and due to the factthat the bell-crank 79 at the opposite ends thereof are disposed atopposite angles to each other, the brake bands 78 will be tightened fromopposite directions, as clearly shown in Figs. 9 and 10. As'the brakebands tighten, the drums 68 and the complementary drum sections 67 willbe retarded. This will tend to hold the bevel ring gears 66 and willcause the bevel pinions 64- and 65 to travel therealong. Rotation of theshafts 62 and 63 will thus be set up and this in turn will drive thegears 58, 59, 60 and 61. Rotation of the gears 58 and 59 will producesimultaneous and equal rotation of the worm gears 54 and 55. The resultwill bethat a loss in driving speed will be established between the gearframe 53 and the gear 69, for, although the frame is movingatitsoriginal rate of speed as driven by the shaft 45, yet the gears 5d and55 are not locked'to produce uniform rotation between the gear frame 53and the gear 69but are moving in a manner to retard the gear 69 whilethe gear frame moves at its original speed. This action will, of course,affect the axle portion'in connection with this particular sleeve 51 andwill cause the vehicle to turn to that side of the roadway, it beingunderstood that the other drum is free to rotate and that the axlesection is rotating'at'its original and normal speed.

In the present instance, the gear ratio is such as to cause the tractiondevices of the vehicle to remain idle when the drums 68 are held.motionless, the reduction produced ception that the gears are sodesigned as to cause a creeping action of the vehicle when the brakedrums are set.

It will thus be seen that the transmission construction here disclosed,embodies means for positively driving the tracknnits of a vehicle at thesame or different speeds-and for producing the variation in drivingspeeds by means which will not require or consume any great amount ofpower and whlch Wl-l-l act positively at all times under the control ofthe operator.

Having thus described my invention, what I claim and desire to secure byLetters Patent is 1. In combination with a driving shaft, a

communication between the bevel gearof the brake drum and the worm gearupon the frame, whereby retardation of the brake drum, while the shaftis being constantly driven, will produce a variation in the speedsofrotation of the shaft and the sleeve.

2. In combination with a driving shaft, a clutch mechanism comprising agearframe secured to the end of said shaft, a pair of worm gearsrotatably supported by said.

frame upon diametrically opposite sides of the shaft, a worm wheel inaxial alignment with said shaft and with which both of said gearsconstantly mesh, a driven sleeve freely rotated upon the shaft and uponwhich the worm wheel is fixed, a reducing gear ciroumscribing thesleeve, and free to rotate in relation thereto, a brake drum carried bythe reducing gear, and reduction gearing connecting the worm gearsWith'the reducing gear, whereby the retardation of the reduction gearbythe ap plication of brake pressure upon the drum will operate saidreducing gears to produce variation in the speed of rotation of thedrive shaft and the-sleeve mounted thereon.

3. A power transmission mechanism for motor-vehicles in which thesteering is effected by varying the relative driving speeds of thetraction device on opposite sides of the vehicle, comprising atransverse shaft operatively connected with the motor, a dividedtransverse shaft parallel to the first mentioned shaft, a pair ofsleeves separately rotatable on the first mentioned shaft, spur gearingconnecting each of said sleeves with one part of the divided transverseshaft, and positive reduction clutches mounted upon the outerextremities of the first mentioned transverse shaft for transmittingmotion to said sleeves, each positive reduction clutch comprising anouter drum to Which a brake is applicable, a ring gear secured Withinthe drum, pinions meshing with said gear two parallel WOI'IH spindlesoperatively connected With said pinions, and a central worm Wheelmeshing with wonns of said Worm spindles, said central worm Wheel beingrigidly secured to the adjacent 1O revoluble sleeve.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witnesses.

ELMER E. \VICKERSHAM.

Witnesses:

O. EHRENFER, R. E. MANN.

